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Question
Find the value of k for which the roots of `9x^2+8kx+16=0` are real and equal
Solution
Given:
`9x^2+8kx+16=0`
Here,
`a=9, b=8k, and c=16`
It is given that the roots of the equation are real and equal; therefore, we have:
`D=0`
⇒`(b^2-4ac)=0`
⇒`(8k)^2-4xx9xx16=0`
⇒`64k^2-576=0`
⇒`64k^=576`
⇒`k^2=9`
⇒`k=+-3`
∴ `k=3 or k=-3`
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